I would recommend chunking the data across multiple UAVOs like we did for that proposed geofence verticies.  Even if you don't normally want more than say 16, put 16 in one UAVO and then make multiple instances.  Then you can address them like

   int32_t histogram_index;
   int32_t histogram_uavo_num = histogram_idx / VIBRATIONMEASUREMENT_BINVALUE_NUMELEMENTS;
   int32_t histogram_uavo_sub_idx = histogram_idx % VIBRATIONMEASUREMENT_BINVALUE_NUMELEMENTS;

It will probably be much more memory efficiency when you are dealing with 16 UAVO versus 256.